Update the class BankAccount of the text so that instances of this class do not allow withdrawals that exceed the balance, and have passwords that work as described below.

The two constructors and the deposit, withdraw, getBalance methods of this class should take an additional final String argument representing the password. In addition, your class should have a method changePassword that takes a new password and the old password as arguments, and updates the account password to be the new password.

The two constructors should initialize the account password to have the value of their String arguments. The other methods should return a String that consists of an informative error message in case of error (that is, if an incorrect password is provided, or there is not a sufficient balance to cover a withdrawal). If there is no error,

• the deposit and withdraw methods should return a message giving the amount deposited or withdrawn, and giving the new balance. They should also modify the account balance appropriately.
• the getBalance method should return the String equivalent of the new balance.
• the changePassword method should update the account password to match its first argument

Passwords should be case sensitive -- that is, you should use a case-sensitive comparison method to check password arguments against the account's actual password.

For this assignment, you should provide a copy of your code on diskette (no CD or email), and hard copies of your code and of the results of your testing with the A6.java file, which is provided on the class web site. Prof. Horstmann's BankAccount.java file is also available from the class web site.

You should know which comments are appropriate for Javadoc and which are not, but you will not be judged harshly on the syntax of your Javadoc comments. Don't forget to update the documentation of your methods to mention the new parameters, and the treatment of errors